Yes, it's the one with the PRI ... Power Reserve Indicator (implemented as a hand in a fan-shaped register) under the '12'.
There has been speculation on WHAT this movement really was & most sources indicate it had Swiss origins, though nobody I've read has gone beyond that with any "definitive" information on it's source.
Well, I was reading through 1 of my favorite watch books @ home [Wristwatches by Brunner & Pfeiffer-Belli] recently and came across a couple of European watches that look suspiciously like this Seiko, and they (conveniently) are labeled as being from the "right" time-frame [ca. 1955]. Both have 17 jewels (and indeed the Seiko came in either 17j or 21j).
One of those European watches was an "Eska" and the other was a "Mondia". They both are configured the same as the Seiko [PRI under the '12' configured as a hand in a register].
They are described in the book as having either an AS 1382 or AS 1382N movement with Flat hairspring, Incabloc shock-protect, and a Glucydur balance.
Could those be the origins of the Seiko 1st Generation Automatic that was a real 'flagship' model of the mid-50s for Seiko??
Well, what else was out there in the same time-period??
Some may not know this, but Gruen also had a PRI Automatic in those days & it is said to be based on a Felsa 1566 or related calibre movement!
The Gruen examples I've seen do have a PRI display 'under the 12', but they are implemented as a rotating wheel in a window cut-out in the dial.
Anyway, here is a shot of a close relative of that Gruen movement, the 550RI:
Here is the Felsa believed to be the base for it:
Now, let's see the Seiko!
If you look to the "right" of and a little "above" the balance assembly in each of those shots showing a balance [relative to how balance is positioned in each shot] you will see quite a bit of difference in the architecture of the Gruen/Felsa and the Seiko. So, it would seem the Felsa [Gruen] is "out" as a candidate.
Now, let's try to other candidate I know of from my book, the AS 1382 (the 1382N in this case). The following is from a watch by "Wyler":
If you compare the winding bridge layout between the AS and the Seiko, you do see a lot of similarity now! Plate and potence layout also looks quite close in other areas!
So, we may just have a "match" there! Now of course, there's some differences - the Seiko uses a shock-protection system that differs from what we see in the Wyler example. The rotor is "cut" differently too.
One other shot of the Wyler's AS showing more detail in the winding system:
As Ranfft describes this movement (in reference to the auto-winding system), "Fig. 3: Sophisticated combination of differential gear and friction clutch: An elastic steel cock (grey) is
pressing three wheels together. The middle wheel has three holes in which balls are circularely rolling between upper and lower wheel. So the balls drive the middle wheel with the difference of upper and lower wheel, driven by wheels on barrel and barrel-arbor respectively. Thus
the planet wheels commonly used in differential gears are replaced by planet balls, which simultaneously act as friction clutch. This assembly fits in just 4mm diameter, and 0.6mm height."
Unfortunately, I have no "movement explosion" shot of the Seiko with similar detail. If anyone DOES have one, it could go a long way to proving whether we indeed have a match here between the Seiko Cal. 11A and the AS 1382(and "N")!
Thanks to Ranfft Database for the reference shots & info on the Swiss movements!